public static async Task DeleteDatabaseAsync()
{
SQLiteAsyncConnection conn = new SQLiteAsyncConnection(Windows.Storage.ApplicationData.Current.LocalFolder.Path + "\\Data.db");
await conn.DropTableAsync <Course>();
await conn.DropTableAsync <Term>();
await conn.DropTableAsync <Exam>();
await conn.DropTableAsync <Lesson>();
Term.ClearData();
Exam.ClearData();
WeekDay.ClearData();
}
public static async Task <bool> UpdateDataAsync()
{
bool updated = false;
WebHelper webHelper = new WebHelper();
if (await webHelper.getAllData())
{
SQLiteAsyncConnection conn = new SQLiteAsyncConnection(Windows.Storage.ApplicationData.Current.LocalFolder.Path + "\\Data.db");
await conn.DropTableAsync <Term>();
await conn.DropTableAsync <Lesson>();
await conn.DropTableAsync <Exam>(); //删除之前的数据
await conn.DropTableAsync <Course>(); //不提示成绩更新情况下，直接删除成绩
await conn.CreateTablesAsync <Course, Term, Lesson, Exam>();
await conn.InsertAllAsync(webHelper.Exams);//update exams;
await conn.InsertAllAsync(webHelper.Terms);
await conn.InsertAllAsync(webHelper.Lessons);
await conn.InsertAllAsync(webHelper.Courses);
Term.ClearData();
Exam.ClearData();
WeekDay.ClearData();
updated = true;
}
return(updated);
////区分有无成绩更新，方便后续扩展出成绩提示
//var previousCourses = terms.SelectMany(term => term.Courses);
//var updateCourses = from course in webHelper.Courses
// let previousCourse = from tempCourse in previousCourses
// where tempCourse.CourseName == course.CourseName &&
// tempCourse.TermNumber == course.TermNumber &&
// (tempCourse.GradePoints != course.GradePoints | tempCourse.MakeUpExamGrades != course.MakeUpExamGrades)
// select tempCourse
// where previousCourse.Any()
// select course;
//var newCourses = from course in webHelper.Courses
// let previousCourse = from tempCourse in previousCourses
// where tempCourse.CourseName == course.CourseName &&
// tempCourse.TermNumber == course.TermNumber
// select tempCourse
// where !previousCourse.Any()
// select course;
//var updatedCourse = updateCourses.ToList();
// var newcourses = newCourses.ToList();
//if (updateCourses.Any() | newCourses.Any())
//{
// try
// {
// await conn.InsertAllAsync(newCourses);
// await conn.UpdateAllAsync(updateCourses);
// }
// catch (Exception)
// {
// await conn.DropTableAsync<Course>();
// var message = new Windows.UI.Popups.MessageDialog("更新本地数据出错，建议或重试，或进入设置删除本地账号和数据或重启应用后再导入");
// await message.ShowAsync();
// }
// updated = true;
//}
}